【摘要】 本文对三种生理相关的正弦入口速度波形的脉动流场内 ,VEC表面的切应力分布进行了有限差分方法的数值模拟。结果表明 :(1)脉动流场与稳态流场中内皮细胞表面的流场分布完全不同 ,脉动流场中内皮细胞表面的切应力变化幅值远大于稳态流场中的值。 (2 )同一时刻 ,每个VEC上的切应力分布是不均匀的 ,细胞形状影响其表面的切应力分布。 (3)在脉动周期的不同时刻 ,细胞表面的切应力分布也是不均匀的 ,切应力分布随时间的变化波形与入口波形相类似 ,但相位有所超前。 (4 )细胞的伸长主要取决于EC表面的最大平均切应力大小。(5 )本章的计算结果可以用于对Helmilinger实验现象的解释。更多还原

【Abstract】 Shear stress acting on the luminal surface of endothelial cells due to shear flow was determined on a subcellular scale. Three types pulsatile state flow (type I: nonreversing flow, type II: reversing flow, type III: oscillatory flow) over a wavy endothelial cell surface was simulated by finite difference method. We obtained: (1) The shear stress amplitude of variation in pulsatile field higher than that in steady flowing field; (2) the fluid shear stress distribution in cell was nonuniform and the magnitude of the shear stress perturbation depended on the value of height/length ratio, and this value increased, with the shear stress increase; (3) the phase of the shear stress distribution was also nonuniform and changed with time and sinusoidal entrance velocity, and at the same entrance rate of flow, the maximum value of shear stress in pulsatile state was much higher than that in the steady state condition; (4) the length growth of the cell depended on the values of average maximum shear stress on the surface; and (5) the calculated results could be used to explain the experiment results obtained by Helmilinger.更多还原